Table 1.

Participants' demographic characteristics, drug-use history, and scores on a test of the capacity for mental imagery.

Measure	Placebo Group	Propranolol Group	p-value
N	15	18
Age (yrs) mean; range	42.1; 24-54	41.6; 26-55	.96
Sex n (%)			.23
Male	9 (60%)	7 (38.9%)
Female	6 (40%)	11 (61.1%)
Race n (%)			.46
African American	12 (80%)	12 (66.7%)
European American	2 (13.3%)	5 (27.8%)
Other	1 (6.7%)	1 (5.6%)
Education (yrs)	11.9	11.9	.60
Employment n (%)			.40
Full time	5 (33.3%)	5 (27.8%)
Part time regular hours	0	3 (16.7%)
Part time irregular hours	4 (26.7%)	2 (11.1%)
Unemployed	6 (40%)	7 (38.9%)
In Controlled Environment	0	1 (5.6%)
Cigarette smoking	14 (93%)	16 (89%)	.99
Cigarettes per day (average ± SD)	14.93 ± 10.87	12.50 ±9.28	.49
Cocaine
Route of Administration n (%)			.09*
Intranasal	1 (7.1%)	0 (0%)
Smoked	9 (64.3%)	17 (94.4%)
Intravenous	4 (28.6%)	1 (5.6%)
Days used in last 30 (mean; range)	10.8; 0-28	16.9; 1-30	.06*
Years of use (mean; range)	9.9; 0-30	10.0; 0-20	.96
Heroin
Route of Administration			.99
Intranasal	8 (53.3%)	10 (55.6%)
Intravenous	7 (46.7%)	8 (44.4%)
Days used in last 30 (mean; range)	1.0; 0-7	1.6; 0.6	.43
Years of use (mean; range)	17.5; 1-30	13.3; 2-28	.10.
More than one substance
Days used in last 30 (mean; range)	9.2; 0-28	17.2; 0-30	.02*
Years of use (mean; range)	4.7; 0-23	3.7; 0-15	.65
Questionnaire on Mental Imagery (mean; range)	75.9; 41-116	77.7; 40-130	.85